allman



(No Model.) 2 Sheets-Sheet 1.

I. F. ALLMAN.

GAS ENGINE.

No. 453,071. Patented May 26,1891

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I. F. ALLMAN.

GAS ENGINE.

No. 453,071. Patented May 26,1891.

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UNITED STATES PATENT OFFICE.

ISAAC F. ALLMAN, OF NEW YORK, N. Y.

GAS-ENGINE.

SPECIFICATION forming part of Letters Patent No. 453,071, dated May 26,1891.

Application filed February 11, 1891. Serial No. 381,021. (No model.)

To all whom it may concern.-

Be it known that I, Isaac F. ALLMAN, of the city, county, and State ofNew York, have invented a new and Improved Gas-Engine, of which thefollowing is a full, clear, and exact description.

The invention consists of certain parts and details and combinations ofthe same, as will be described hereinafter, and then pointed out in theclaims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure l is aside elevation of the improvement with parts in section.Fig. 2 is a sectional front elevation of the same on the line 00 a: ofFig. 1; and Fig. 3 is a sectional plan View of the cylinder on the liney y of Fig. 2.

The improved gasengine is provided with aWater-jacketed cylinder A, openat its upper end and closed at its lower end by a head B, extendingpartly into the cylinder A, and having in its inner end a semi-sphericalrecess B, as is plainly illustrated in Fig. 2. In the cylinder A isfitted to reciprocate the piston 0, having its inner end formed with asemi-spherical recess 0, similar to the recess B, so that when thepiston O is in its lowermost position, as indicated in Fig. 2, the tworecesses form a hollow sphere. The piston O is pivotally connected withthe pitman D, connected with the crank-arm E, secured on the maindriving-shaft F.

In the cylinder A, near its lower end, is formed an inlet-port a,leading from a valveohamber G, provided with a valve-seat G, on which isadapted to be seated a self-closing valve I-l, )rovided with avalve-stem H, extending to the outside and carrying on its outer end aspring H for holding the valve H on its seat G. The stem II is fitted toslide in suitable bearings in the casing forming the valve-chamber, thesaid valve stein being placed vertically, so that the valve 1-1 isselfclosing by gravity, assisted by the spring H The space below thevalve H is connected with an air-inlet pipe I, through which air ontersto form the explosive mixture with the gas which passes to thevalve-chamber by a gas-pipe J, containing the usual valve J forregulating the amount of gas admitted to the valve-chamber. The gas-pipeJ opens into a semicircular recess G formed in the valve chamber G nextto the seat G, small apertures G leading from the said semicircularrecess G into the seat G. Thus when the valve G is closed the said smallapertures G are closed and gas cannot pass from the pipe J to thevalve-chamber. When, however, the valve H opens, air from the pipe I andgas from the pipe J can pass through the valve-seat G into thevalve-chamber G and from the latter to the port a.

Into the valve-chamber G, above the valveseat G, opens the open end ofthe pipe K, secured in the valve-chamber and extending to the outside,its outer end being closed by a suitable cap. The outer end of the pipeK passes into a chimney K, adapted to be heated by a Bunsen burner.

In the lower part of the cylinder 0 is arranged a small igniting-port b,opening into the semi-spherical recess 0, and adapted to connect withthe port a when the said piston nears its lowermost position. (See Fig.2.) A feed-groove 0 leads from the port I) to the extreme lower end ofthe cylinder G, and serves to feed gas through the port a to thevalve-chamber G. At about the middle of the cylinder A is arranged alarge main exhaustport d, connecting with an exhaust-pipe L discharginginto a pot (not shown) connected with the chimney.

In the lower part of the cylinder A, about opposite the port a, isarranged an exhaustport 6, leading to a relief-valve N, provided with anoutlet N, adapted to be connected by a pipe With the pot into which themain exhaust-pipe L discharges.

seated an inwardly-opening valve N secured on a valve-stem N fitted toslide in the valve N, and extending to the outside, carrying on itsouter end a spring N for holding the valve N to its seat N The extremeouter end of the valve-stem N is adapted to be pressed by an armO,secured to a shaft 0, extending transversely and carrying an arm 0adapted to be pressed by a collar 0 fastened on an eccentric rod 0,connected with an eccentric 0 held on a gear-wheel O in mesh with apinion 0 secured to the main shaft F. When the latter is rotated, thepinion O imparts a The relief-valve N is provided with a valve-seat N onwhich is rotary motion to the gear-wheel O, which, by the eccentric 0the rod 0 and the collar acts on the arm 0 so that the shaft 0 isturned, whereby the arm 0 presses on the valve-stem N to move the valveN inward to establish communication of the relief-valve N with the porte. The proportion of the pinion O and the gear-wheel O is such that thevalve N is held open during every second downstroke of the piston O.

The governor for controlling the amount of gas passing through the pipeJ to the valvechamber Gis arranged as follows: The stem of the valve Jrests on the free end of the lever J provided with a wedge-shaped top Jon which is adapted to travel a friction-roller J held on the lower endof a leverJ, pivoted at J to the main frame. The lever J extends upwardand carries on its extreme upper end a friction-roller J resting againstthe outer face of a collar P, mounted to slide on the hub Q, of thepulley Q, secured to the main driving-shaft F. The collar P is providedwith an annular groove engaged by arms of two bell-crank levers R, eachfulcrumed in the pulley Q, and each carrying a weight R, as is plainlyshown in Fig. 1. The outer or weighted ends of the levers are connectedwith each other by a spring S. A spring J presses on the lever J underthe wedge J and the said lever is also provided with a set-screw J 9 forlimiting the swinging motion of the said lever.

The operation is as follows: When the several parts are in the positionshown in Fig. 2 and the piston 0 makes its first upward stroke, thevalve N is seated and the lower end of the piston soon uncovers the porta, whereby full communication is established between the valvechamber Gand the interior of the cylinder A. The suction caused by theupwardly-moving piston 0 opens the valve H against the tension of itsspring H so that the air can pass to the said chamber from the pipe I,and gas also enters from the pipe J, passing through the annular recessG2 and the small apertures G opening into the seat G. The air passingthrough the seat Gr thus readily mixes with the gas passing through theapertures G so that a complete mixture of gas and air takes place, themixture passing through the port a into the cylinder A. As soon as thepiston ceases its upstroke the suction ceases and the valve H seatsitself on its seat G, so that the gas and air are shut oit. The pistonon its downstroke compresses the mixture of gas and air in thecylinderA, and at the same time part of the mixture is pressed into thevalvechamber G. When the piston nears its lowermost position, thefeed-groove c still maintains communicationbetweenthe cylinderA and thevalve-chamber G, and when finally the ignitin g portb registers with theport a then an ignition of the mixture takes place, caused by the gasbeing ignited in the hot pipe K. The force of the explosion forces thepiston O 011 its second upward stroke, and when it nears the limit ofits upward stroke its lower end uncovers the main exhaust-port cl, sothat the main part of the utilized explosive mixture passes out throughthe said port d into the exhaust-pipe L. hen the piston 0 moves downwardon its second stroke, the valve N opens, as previously described, and isheld open by the action of the arm 0, so that the residue of the exhaustof the explosive mixture can pass out through the port 6 into the reliefexhaust-valveh and from the latter to the pot into which the mainexhaust had previously been discharged. It is understood that when theexplosion takes place the valve H remains on its seat by the pressure inthe cylinder, so that the said valve will not open on the second upwardstroke of the piston. It is further understood that when the piston O ison its first upward stroke sucking in the explosive mixture, then thelatter cannot escape through the port d when it is uncovered by thepiston O, as the back-pressure from the pot and pipe L is sufficient toprevent the escape of the explosive mixture. \Vhen,however, theexplosion has taken place on the second upward stroke of the piston, aready escape is furnished by the exhaust-port d, which is madesufficiently large for the purpose. (See Fig. 3.) The residue of theexhaust is discharged through the exhaust relief-valve, as previouslymentioned. Then the shaft F exceeds its normal speed, the weighted ballsR of the governor fly outward, thus moving the collar P inward, wherebythe inner end of the lever J swings inward with the collar P and itslower end J 4 moves down on the incline of the wedge J The spring J 8now acts on the lever J so that the valve J closes, thereby cutting offthe supply of gas, whereby the mixture of gas and air in the cyl inderloses some of its force, thus finally reducing the speed of the mainshaft F. hen the shaft F- runs at a normal rate of speed, the balls R,again assume their natural position, aided by the action of the springS, so that the collar P slides outward and moves the lever J to itsformer position, whereby the friction roller J again presses on thewedge J thereby opening the valve J sufficiently to admit the regularamount of gas to the valve-chamber G.

It will be seen that the valvechamber G and the relief-valve N arearranged on the outside of the cylinder A, and can thus be readily takenoff and examined and replaced, if necessary, without disturbing thecylinder A and its piston 0.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The combination, with the cylinder hav= ing an imperforate head,opposite inlet and outlet ports a e in the cylinder above the head, themain exhaust (Z in the cylinder above said ports, and the piston 0,working in the cylinder and provided with a port I) to register withport a, of the chamber G at the port a, having a gas and air inlet and avalve controlling both and provided with a stem leading out- Ward, andthe exhaust-chamber N, having a spring-seated valve controlling port 6and provided with a stem extending outward and actuated from the mainshaft, substantially as set forth.

2. The combination, with the cylinder, the piston and the main shaft,the gas and air chamber G, communicating with the cylinder and having avalve-seat G, air-inlet I, recess GR under the seat, apertures G leadingfrom the recess through the seat, gas-pipe J, leading to said recess andhaving a valve J, provided with a downward-extending stem, the valve H,closing down on the valve-seat and apertures and having adownward-extending stem H, and a spring holding the valve closed, of thehorizontal lever pivoted between its ends to rock vertically andextending at its inner end under the stem of valve J a spring J 8 underthe opposite end of the lever, a cam J 3 on the upper side of the outerend of the lever, a vertically-extending lever J pivoted at J and havingits lower end provided'with a roller engaging the said cam, a slidingcollar on the main shaft engaging the upper end of the lever J andgovernor-balls mounted on pivoted levers or arms engaging the saidcollar, substantially as set forth.

3. The combination, with the cylinder A, having an imperforate head B,closing its lower end, and having a concavity B in its inner face, thediametrically-opposed inlet and outlet ports a e and their valvemechanisms, and the upper exhaust-port d, of the piston 0, having alower concave end and provided in said concave portion with a lateralignition-port b to register with the port a, substantially as set forth.

4. In a gas-engine, the combination, with a cylinder provided with aninlet-port, of a piston fitted to slide in the said cylinder andprovided With an ignitingport and a feed groove adapted to register withthe said inletport, a valve-chamber held on the said cylinder andconnected with the said port, and an externallyheated pipe extending atits open end into the said valvechamber, substantially as shown anddescribed.

ISAAC F. ALLMAN. Witnesses:

THEO. G. HOSTER, EDGAR TATE.

